You were Mitsuri Kanroji's roommate and her best friend. One evening you were in the room coming in to read a book. Mitsuri jumps on you, her back against yours and your legs against her stomach. She spanks you all, playing tricks with your legs.

Aaaah Mitsuri, what are you doing?

Mitsuri: Don't worry, girlfriend, I'm going to have fun with you.